The invention relates to an apparatus for fixing a cable guidance hose to a device, such as in particular a robot.
Such cable guidance or protective hoses are mainly used on robots having several parts pivotable relative to one another, particularly robot arms, in order to guide externally of the robot electrical cables for the power supply of the robot or a tool located in a robot hand. As distance or spacing changes between individual points of the robot occur during operation, the cable guidance hoses must on the one hand be able to absorb length changes and on the other must be loaded to the minimum during robot movements in order to ensure a high level of stability and prevent untimely failure.
At the end of the cable guidance hose the cables guided therein must be held so as not to rotate and also axially fixed to prevent cable damage by sliding, twisting and extraction from the cable guidance hose and so as to ensure an adequate tension relief of the cables and an adequate relief of the connections for the cables to the robot or tool. However, the cable guidance hose must also be axially fixed, but must be rotatable about its median longitudinal axis on the robot in order to avoid twisting as a result of robot movements during operation.
It is known to fix the cables in bundle form by clamping to the robot in axially fixed and non-rotary manner and to separately mount on the robot in rotary manner about its median longitudinal axis said cable guidance hose. It is disadvantageous that two different bearing parts are required, which is both complicated and costly and also a relatively large amount of space is needed, which is only available to a limited extent particularly in the vicinity of the highly mobile robot hand generally pivotable about several axes. It is also known to fix both the cable guidance hose and the cables together to the robot so as to rotate about the median longitudinal axis of the hose, which for the indicated reasons can lead to cable damage.
The problem of the invention is to propose an inexpensive, space-saving apparatus of the aforementioned type, which in particular takes account of the indicated requirements with respect to the damage-fixing of a cable guidance hose and the cables located therein to a mechanical device, such as in particular a robot.
In the case of an apparatus of the aforementioned type, the invention solves this problem in that the cable guidance hose is held in axially fixed manner and at least one holding part connected thereto is held in axially fixed and non-rotary manner on the device.
Thus, the cable guidance hose is held in axially fixed and further holding parts are held in non-rotary and axially fixed manner to the device, such as the robot.
In preferred developments it is provided that the holding part is held in non-rotary manner in the clip and in particular that the holding part receives a cable clamping piece holding in non-positive manner the cables in the cable guidance hose. Here there is a clip for the axially fixed securing and a cable clamping piece holding positively the cables and also one end of the cable guidance hose and between the cable clamping piece and the clip is provided a non-rotary connection, whereas the connection between the cable guidance hose and the clip in particular permits relative mutual rotation.
The apparatus according to the invention permits a compact and easily fittable and dismantlable arrangement of the cables together with the cable guidance hose and a relative rotatability of the cable clamping piece receiving in positive manner the cables with respect to the cable guidance hose is ensured, in that the cable clamping piece is held in non-rotary axially fixed manner in the clip, whilst the cable guidance hose end is mounted in axially fixed, but rotary manner in the same clip. It is particularly suitable for fixing the cable guide of a robot in the vicinity of the robot hand, in that the clip is so positioned in the area of the robot hand that the cables used e.g. for the power supply of a robot tool are fixed by means of the cable clamping piece on the side facing the robot hand and the cable guidance hose on the side remote from the robot hand in said clip.
In a preferred construction the clip is provided on the inside with at least one holding profile for the axially positive fixing of a holding part for the cable guidance hose and a holding part for the cable clamping piece with in each case a profile complimentary to the holding profile of the clip. The holding profiles of the clip in particular have an adequate axial spacing to ensure that there is a gap between the facing end faces of the cable guidance hose and the cable clamping piece, so as not to impair the relative rotatability of the cable guidance hose with respect to the cable clamping piece.
In order to ensure a rapid and easy installation, the holding part for the cable guidance hose preferably has two half-rings, which are equipped on the inside with a holding structure for the axially positive fixing on the cable guidance hose circumference. If the cable guidance hose at least terminally in cross-section has a corrugation, particularly a rectangular or trapezoidal corrugation, the holding structure of the holding rings for the cable guidance hose has in preferred manner a holding structure engaging in the corrugated structure of the cable guidance hose. Alternatively the holding structure of the holding rings can e.g. be constructed for the reception of a circumferential bead or the like shaped at the cable guidance hose end.
In accordance with the construction of the holding part for the cable guidance hose, in a preferred construction also the holding part for the cable clamping piece has two half-rings, which are equipped on their inside with a holding structure for the axially positive fixing to a fixing structure located in complimentary manner thereto on the circumference of the cable clamping piece.
For the non-rotary fixing of the cable clamping piece in the clip preferably at least one half-ring of the holding part for the cable clamping piece can be secured in non-rotary manner by means of a pin traversing the same both to the cable clamping piece and to the clip and in particular on the end face of the clip facing the cable clamping piece is provided a groove for receiving one end of the pin and on the cable clamping piece circumference in the vicinity of the fixing structure a recess for receiving the other end of the pin.
In order to ensure increased protection of the cables against abrasion through the rotating hose, according to a further development the cable clamping piece has a spigot engaging in the cable guidance hose and which covers the connection point between the cable clamping piece and the cable guidance hose on the inside thereof.
In order to ensure an easy equipping of the cable clamping piece with the cables, the cable clamping piece is preferably constructed in the manner of a clamp with several axially positioned holding channels for the non-positive securing of the cables and is in particular made from an elastic material, said holding channels being connected by means of slots to the clamping piece circumference. In this way the cables can be easily introduced by means of the slots into the holding channels and, if cables have to be replaced, can be removed from said channels.
In order to ensure a non-positive connection between the cables and the cable clamping piece, preferably a tension clip engaging round the clamping piece on its side remote from the clip is provided and the tension thereof is in particular variable, so that cables with different diameters can be fixed in the cable clamping piece.
As indicated, the clip can in particular be secured to part of the robot, particularly in the vicinity of the robot hand, by random holding means, such as screws, bolts, clasps, etc.
In a highly preferred development of the invention, a holding part has a sleeve with a spherical segment outer face and with respect to the clip median longitudinal axis the sleeve is held in both rotary and pivotable manner thereon. This ensures a maximum protection of the cable guidance hose even against bending and torsional moments acting thereon.
This preferred development of the holding of the cable guidance hose in the manner of a ball bearing ensures in addition to a free rotatability of said hose with respect to the clip, a pivotability thereof with respect to the median longitudinal axis of the clip. Thus, the cable guidance hose is effectively relieved, in that it is protected against torsional and bending stresses, which leads to an increased service life and makes possible certain applications for the first time. Thus, the apparatus according to the invention is particularly suitable for fixing the cable guide of a robot in the vicinity of the robot hand, in that the clip is so positioned in the vicinity of said hand that the cables e.g. used for the power supply of a robot tool can be fixed by a cable clamping piece to the side facing the robot hand and the cable guidance hose on the side remote from the robot hand in rotary and pivotable manner in the clip. Whereas the cable guidance hose is preferably held in freely rotary manner on the clip, it is preferably pivotable by approximately 30xc2x0, particularly approximately 20xc2x0 in each direction relative to the clip median longitudinal axis.
In order to ensure a simple and rapid installation, the sleeve preferably has two half-shells, which are equipped on their inside with shapes for the axially positive securing to the circumference of the cable guidance hose. If the cable guidance hose at least terminally has in cross-section a corrugation, particularly a rectangular or trapezoidal corrugation, the shapes of the half-shells of the sleeve preferably engage in the corrugation of the cable guidance hose. Alternatively the shapes of the sleeve are e.g. constructed for receiving a circumferential bead or the like formed on the cable guidance hose end.
Whilst the sleeve can fundamentally be directly secured to an inner profile of the clip complimentary to its spherical segment, in a preferred construction the holding part also has a ring bearing receiving the sleeve with an inner face complimentary to the spherical segment outer face of the sleeve and in particular the ring bearing is provided on its side remote from the sleeve with a holding profile for securing on the clip. Thus, the cable guidance hose can be more easily fitted and it is also possible to use a conventional, simple, inexpensive clip.
The holding profile of the ring bearing can either be fixed to a profile of the clip complimentary thereto, or it can be fixed to an adaptor ring profile complimentary thereto and which has on its side remote from the ring bearing a fixing profile for fixing on a clip profile complimentary thereto. The latter variant more particularly permits a space-saving arrangement of the cable guidance hose if the adaptor ring has on its side facing the ring bearing a larger diameter than on its side remote therefrom or facing the clip, so that the clip diameter can roughly correspond to the hose diameter. For purposes of a simple, rapid installation, the adaptor ring preferably has two half-rings.
Appropriately on its holding profile the ring bearing can either be fixed directly or via the adaptor ring in axially fixed manner to the clip.
As stated, in a preferred construction on the clip side remote from the cable guidance hose can be secured in axially fixed and non-rotary manner a cable clamping piece non-positively holding the cables. Thus, the clip is provided both for the axially fixed holding of the cable clamping piece and also one end of the cable guidance hose and between the clamping piece and the clip there is a non-rotary connection, whilst the connection between the cable guidance hose and the clip remains pivotable and rotatable relative to one another. The non-rotary connection the clip and the cable clamping piece can e.g. be ensured by complimentary polyhedral profiles, by holding pins or random known means.
The clip is preferably a tension clip with a base fixable to the machine by random holding means, such as screws, bolts, clasps, etc. and a top braceable and articulated thereto by means of a shackle. In this way the ring bearing of the holding part or the adaptor ring is firmly clamped in the tension clip and is preferably held in non-rotary manner by frictional forces.
The invention also relates to a mechanical device, such as in particular a robot with at least partly externally positioned cables, especially supply cables of robot tools and which is equipped with an apparatus of the aforementioned type.